1. Technical Field
The present disclosure relates generally to an electrosurgical instrument and, more particularly, to an electrosurgical pencil having a motion detector for controlling the electrosurgical output thereof.
2. Background of Related Art
Electrosurgical instruments have become widely used by surgeons in recent years. Accordingly, a need has developed for equipment that is easy to handle, is easy to operate, and is reliable and safe. By and large, most surgical instruments typically include a variety of hand-held pencils, e.g., electrosurgical pencils, forceps, scissors and the like, and electrosurgical pencils, which transfer energy to a tissue site. The electrosurgical energy is initially transmitted from an electrosurgical generator to an active electrode which, in turn, transmits the electrosurgical energy to the tissue. In a monopolar system, a return electrode pad is positioned under the patient to complete the electrical path to the electrosurgical generator. A smaller return electrode is positioned in bodily contact with or immediately adjacent to the surgical site in a bipolar system configuration.
For the purposes herein, the term electrosurgical fulguration includes the application of an electric spark to biological tissue, for example, human flesh or the tissue of internal organs, without significant cutting. The spark is produced by bursts of radio-frequency electrical energy generated from an appropriate electrosurgical generator. Generally, electrosurgical fulguration is used to dehydrate, shrink, necrose or char tissue. As a result, electrosurgical fulguration instruments are primarily used to stop bleeding and oozing of various surgical fluids. These operations are generally embraced by the term “coagulation.” Meanwhile, electrosurgical “cutting” includes the use of the applied electric spark to tissue which produces a cutting effect. By contrast, electrosurgical “sealing” includes utilizing a unique combination of electrosurgical energy, pressure and gap distance between electrodes to melt the tissue collagen into a fused mass.
It is known that certain electrosurgical waveforms are preferred for different surgical effects. For example, a continuous (i.e., steady) sinusoidal waveform is preferred to enhance the cutting effect of the electrosurgical blade in an electrosurgical pencil or enhance the cooperative effect of the two opposing jaw members. A series of discontinuous, high energy electrosurgical pulses are preferred to enhance the coagulation of biological tissue. Other types of electrosurgical waveforms are preferred for electrosurgical “blending”, “shorting” or fusing tissue. As can be appreciated, these waveforms are typically regulated by the generator and are generally dependent upon the desired mode of operation manually selected by the surgeon at the onset (or during) the operation.
As used herein, the term “electrosurgical pencil” is intended to include instruments which have a handpiece which is attached to an active electrode and are used to coagulate, cut, and seal tissue. The pencil may be operated by a hand-switch (in the form of a depressible button provided on the handpiece itself) or a foot-switch (in the form of a depressible pedal operatively connected to the handpiece). The active electrode is an electrically conducting element which is usually elongated and may be in the form of a thin flat blade with a pointed or rounded distal end. Typically, electrodes of this sort are known in the art as “blade” type. Alternatively, the active electrode may include an elongated narrow cylindrical needle which is solid or hollow with a flat, rounded, pointed or slanted distal end. Typically, electrodes of this sort are known in the art as “loop” or “snare”, “needle” or “ball” type.
As mentioned above, the handpiece of the pencil is connected to a suitable electrosurgical source (e.g., generator) which supplies the electrosurgical energy necessary to the conductive element of the electrosurgical pencil. In general, when an operation is performed on a patient with an electrosurgical pencil, energy from the electrosurgical generator is conducted through the active electrode to the tissue at the site of the operation and then through the patient to a return electrode. The return electrode is typically placed at a convenient place on the patient's body and is attached to the generator by a return cable.
During the operation, the surgeon depresses the hand-switch or foot-switch to activate the electrosurgical pencil. Then, depending on the level of radio-frequency electrosurgical energy desired for the particular surgical effect, the surgeon manually adjusts the power level on the electrosurgical generator by, for example, rotating a dial on the electrosurgical instrument. Recently, electrosurgical pencils have been developed which vary the level of electrosurgical energy delivered depending on the amount of drag sensed by the active electrode or by the degree the hand-switch has been depressed by the surgeon. Examples of some of these instruments are described in commonly assigned U.S. Provisional Application Nos. 60/398,620 filed Jul. 25, 2002 and 60/424,352 filed Nov. 5, 2002, the entire contents of which are hereby incorporated by reference.
Accordingly, a need exists for an electrosurgical pencil which is activated without the use of hand-switches or foot-switches and which can automatically control the electrosurgical output from the electrosurgical generator without manual intervention by the surgeon.